Universal fastening for lamp-socket casings



= 3 L 1930. E. H. FREEMAN 1,769,829

UNIVERSAL FASTENING FOR LAMP SOCKET CASINGS Filed Jan. 19.1926

i 1 ml ulu n Hill Ls"! flnnii w gwwntoz Efgfleenmn atent'ed July 1, 193a UNITED STATES PATENT; OFFICE EDGAR H. FREEMAN, OF 'IRENTON, NEW JERSEY, ASSIGNOR 'IO CIRCLE F MFG. 00., O1 TRENTON, NEW JERSEY, A. CORPORATION OF NEW JERSEY UNIVERSAL FASTENING FOR LAMP-SOCKET CASINGS Application filed January 19, 1926. Serial No. 82,325.

This invention relates to the cap and shell type of casing for electric lamp sockets and particularly has in view a novel fastening therefor which permits a universal adjustg ment for the shell in looking the same to the lllodern requirements demand a construction of lamp socket casing wherein a plurality of lockin positions are provided between the metallic shell and the metallic cap of the easing thereby to permit the shell to be so positioned when locked to the cap as to present the switch key of a key socket in a readily accessible and convenient position for manipulation, and also to permit the shell of a keyless socket to be quickly and easily snapped into its locked relation to the cap without special care or attention being required on the part of the workmen, as to the relative poso sition of the parts when the shell is pushed into telescoping locking engagement with the Accordingly, the present invention contemplates a simple, reliable and POSltlVB fastenparts of a lamp socket casing which admits of a universal circular adjustment for the shell so that the same locking means are ef fective in practically every position within the 360 of the circumference of the cap.

A further and distinctive object of the invention is to provide a type of fastening, not only permitting of the umversal adJustments referred to, but also, a fastening which may easily and economically be made, and one that is entirely confined and concealed within and behind the flange of the cap, when the shell and the cap are in assembled locked relation, thereby obviating all obstructions and unsightly projections on the exterior of the socket casing, which is the condition prevailing with some types of fastenings for the cap and shell of lamp socket casings.

- Another object of the invention is to provide a fastening of the type and character referred to which definitely and easily guides the two parts of the easing into their telesc'oping locked engagement, and when so engaged secures the cap and shell together 1n such a firmly locked condition as to secure the mg connection between the shell and cap shell against displacement or unlocking either in a direction longitudinall of the casing, or by rotative movement. n other words, the improved cap and shell fastening of the present invention provides for locking the parts against relative rotation and also against longitudinal separation.

With these and other objects in view which will appear to those familiar with this art the invention consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed; and while the invention is susceptible of structural modification without departing from the essentials thereof, a preferred and practical embodiment is shown in the accompanying drawings, in which Figure 1 is a side elevation of a lamp socket casing constructed in accordance with the present invention and showing the cap and shell slightly separated, but in proper relative position to permit of the shell being illserted'and locked within the flange of the cap.

Figure 2 is a similar view showing the shell and cap of the casing telescoped and locked.

Figure 3 is an enlarged detail sectional view on the line 33 of Fig. 1.

Figure 4 is an enlarged detail sectional view on. the line a-a of Fig. 2.

Figure 5 is an enlarged detail view showing more clearly the structural characteristics and interlocking relation of a catch projection on the cap with one of the locking projections of the shell.

Figure 6 is a detail sectional View on the line 6-6 of Fig. 2, the line of section being indicated by the line 66 of Fig. 5.

Figure 7 is a plan view of the cap inverted showing the inwardly deflected annular catch projections.

The novel cap and shellfastening constituting the present invention may be employed in connection with any standard or'approved type of two-part caslng for electrical lamp sockets, but the conventional form of lamp socket casing with which the invention usually and preferably is associated comprises the metal shell 1 and the cap 2, the latter being provided with the usual collar 3 for attach- 100 ment to the fixture and with the 1peripheral flange or skirt 4 which telescopica y receives one end of the shell 1. Also in carrying forward the invention the same utilizes the slot 5 formed longitudinally in the body of the shell 1 and extendin to and 0 en throu h the edge of the she which escopically ts within the flange or skirt 4 of the cap. This slot 5, for the purposes of the present invention is termed herein, a longitudinally disresilience slot, which in a key socket 18 of a suflicient size to rmit the switch key to project therethro'ug but in a socket of the ke less type need only be of suflicient size an le to provide suflicient resiliency for the slotted end of the shell to permit of the automatic locking action and to rmit the manual release of the parts as ereinafter more full explained.

Referring more articularly to the details of the improved astening constituting the resent invention it will be observed from the raw' that the end edge of the shell 1 which ts and locks within the flange or skirt of the cap is provided with ribs and ves throughout the full 360 of its circum erence. These ribs and grooves are shown clearl in Figs. 1, 3 and 6 of the drawings and it wi 1 be seen that they are formed so as to leave no projections of any character beyond the outside surface or diameter of the shell. This makes a conformation involving the longitudinally disposed guiding grooves 6, closed at their lower ends and o ned at their upper ends and the longitudina y disposed outwardly projecting ribs 7 alternating with and between the said ves 6. This formation is uniform throughout, the gpidin grooves 6 all being of the same widt and ength and the spacing of the outwardly projecting rib 7 being uniform about the circumferential edge portion of the shell 1.

Preferably at diametrically op osite locations on the shell are formed the diametrically opposite pairs of outwardly deflected and substantially downwardly extending locking projections 8 formed by transversely slitting the shell body as at 9 and pressing the cut metal outwardly to produce the pro ections 8 which assume a substantially half-moon form with the convexed rounded outer guidingsurface 10 and the bottom out edge 11 forming the locking edge which has a flat locking enga ement with t e corresponding cut ed e 12 0 any one of the corresponding inwar ly deflected catch projections 13 pressed inwardly from the flange or skirt 4 of the cap. The inwardly deflected and substantially upwardly extending spaced catch projections 13 are formed in a continuous annular series on and within the flange or skirt 4 of the cap at regularly spaced intervals to provide for the universal adjustments of the shell herein referred to. Each of the said catch rejections 13 is formed by transversely slitting the cap 1,vee,eae

flange as at 14 and ressing the pro'ections 13 inwardly, and is of substantia y halfmoon shape whereby the inner convexed rounded guidin surface 15 has a free sliding enga ment wit the corresponding surface 10 o a locking projection 8 when the shell is telescopically inserted into the flange or skirt of the cap.

The catch projections 8 on the shell are preferably arranged in pairs, one projection of each air lying in a groove formed by flute ing the s ell, and said pairs are preferably arranfied at diametrically (apposite oints on the she as will be observe rom i 1. One pair of catch projections 8 is form in a location ad'acent the resilient slot 5 and immediately a ve that ortion of the shell free to move inwardly w en the parts are telesco ically united, or when manually pressed in y the finger or thumb for the purpose of releasing that pair of the lockin projections from the catch projections of t e cap with which they engage. fter such release of the lock ingtgrojections a mere tilting of the shell out of e ca will permit a complete disengagement an release. Also, in conection with the catch rejections 8 it will be noted that the same are ocated entirely within the ooves or valleys of the flutes, and therefore ve no projection beyond the exterior surface or diameter of the shell. 7

In assemblin the cap and shell the same maybe dispose in the relative relation shown in ig. 1, wherein the bottom of the grooves of the shell carrying the locking pro ections 8 are aligned with a pair of corres nding catch projections of the cap, the she I being merely shoved into place in a straight long1- tudinal line with'the projections riding one over the other, the portion of the shell next to the slot 5 moving inwardl to rmit of this action, and then snap ing ack lnto place when the projections 8 c ear the edge of the catch pro ections 13.

Ordinarily the cap 2 is attached to a fixture nipple and is therefore held rigidly locked in a fixed position. The socket interior is then wired and the shell 1 slipped over the same and then moved into telescoping relation with the cap as previously indicated, namely, by a straight thrust longitudinally or along the axis of the shell.

In order to release the cap and shell it is simply necessar to disenga e the downwardly and outwar ly dispose locking rojectlons from the inwardly and substanti y upwardly disposed catch projections 13 and in order to accomplish that result thumb or finger i ressure ma be exerted on the part marked ress on s ell thereby to move the cut edge 11 of the locking projection 8 out of line with the eorrespondin cut edge 12 of the catch'projection 13 of Ehe cap, and the shell may be rocked on the opposite air of catch projections 8 so as to re ease it om the cap.

. Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor detailsof construction may be resorted to, without de arting from the spirit of the invention an scope of the appended claim.

An electric socket casing comprising a shell provided with a longitudinally extending groove opening through the end of the shell, a locking projection struck outward from the bottom wall of said groove, said projection having an outwardly convexed edge disposed in a plane substantially parallel to the plane ofthe end of the shell, said projection further being tapered in all directions from said edge towards the end of the shell and merging into the bottom wall of the groove, the width of said projection being less than the width of the groove, a cap including a circular wall to fit-over the end of said shell, and a projection struck inward from said circular wall for cooperation with said shell projection, said cap projection having an in Wardly convexed edge disposed in a plane substantially parallel tothe plane of the end of the cap, said projection further being tapered in all directions from said edge tm wards the end of saidcircular wall and merging into the latter, the circular wall of the cap being uninterru ted'except by the projection struck there rom, and the width of said projection being less than the 'width of the groove in the shell and slightly greater than the distance from the side edges of said shell projection tothe side walls of said roove whereby, when the cap is engaged over the shell with the projection thereon entered in the groove of the shell, limited rotation of the cap relative to the shell enables the projections on the cap and shell to spring pass one another substantially in side to side relation.

' In testimony whereof I hereunto afiix my signature.

v EDGAR H. FREEMAN. 

